Current versus Expected behavior

Current: www.dokumentprofi.de and even the plain project alias dokumentprofi-de.vercel.app return 404 Not Found (X-Vercel-Error: NOT_FOUND), despite the production deployment being READY and correctly aliased.

Expected: Domain should serve the production deployment (200 OK), like my other working project in the same team.

Code, configuration, and steps that reproduce this issue

Moved domain dokumentprofi.de from project dokumentprofi to a new project dokumentprofi-de via the API (DELETE + POST /v9/projects/{id}/domains). Since then:

• dokumentprofi.de (apex) correctly 308-redirects to www.dokumentprofi.de
• www.dokumentprofi.de returns 404
• dokumentprofi-de.vercel.app (no custom domain involved at all) also returns 404

Verified via API: domain shows verified: true, deployment is READY, aliasAssigned: true, aliasError: null, and vercel alias ls shows both domains correctly pointing to the current production deployment. DNS is Vercel-managed nameservers, confirmed correct directly against ns1.vercel-dns.com.

Tried: multiple redeploys, removing + re-adding the domain to the project via API, waiting 12+ hours. Nothing resolved it.

Project information

Project: dokumentprofi-de (Hobby plan), Next.js 16.2.9, Node 24.x. Comparison project dokumentprofi (same team, same settings) works fine and serves dokumentprofi.at without issue.